Field of the Invention
The invention relates generally to methods and systems for simulations of dynamic motion and position and, more specifically, to methods and simulations for such simulations used in video games.
Description of the Related Art
Sports simulation games are a popular component of the video game market. Although much progress has been made, certain games still lack the game play flow of the sports which they purport to simulate. For example, video games that simulate the game of basketball have become very popular. Sports and simulation games, such as flight simulators, have become a major industry unto themselves.
Sports simulations present particular challenges in terms of game design and execution because gamers are familiar with the real-world games. In contrast with other types of games (e.g., fantasy games), where the environment and interactions between game entities are completely at the discretion of the game creators, aspects of sport simulations are dictated by the real-world sport itself. As a result, discrepancies between the virtual and real-world versions of a given sport are readily apparent to gamers. This is especially true with sports, such as basketball, that are easily accessible either on television or through physical participation.
Many would consider the fundamental gamer objective in a video game is to have fun. In sport simulation games part of the fun is realistic competition. In competition of any type, the objective is always the same: to win. Gamers will construct strategies within the simulated world in order to achieve this one objective. The greater the error between the simulation and the corresponding real world sport, the greater the discrepancies between these gamer constructed strategies and those of the sport itself. For games which are billed as sport simulations, and for the gamers who purchase and play these games, an accurate simulation of dynamic motion and position is critical.
Certain sports lend themselves to simulation more so than others. For instance American football, with its discrete downs, resets at the line of scrimmage, and highly scripted plays, allows for accurate simulation. On the other hand, in sports such as basketball and soccer, a single instance of continuous play lasts much longer on average. Accordingly, simulation errors have greater time to accumulate and to become more apparent to the game player.
While scripted plays in American football are designed to create an opening which is instantly exploited, the scripted portion of a basketball play is used to create an opening which is often just the beginning of an offensive sequence. An initial opening is usually not large enough to instantly exploit, but does cause a sequence of rotations and player movements that can be used to create ever larger openings, which may be ultimately exploited. The result of this game play pattern is that continuous play sequences are not as mechanical, relying much more on flow and individual decisions.
For example one challenge in basketball simulation is the discrete nature of actions and movements. On many systems, a particular action/movement is executed with a directional input from thumb sticks and a combination of buttons. This input set is then mapped to a corresponding animation, which in turn takes a certain amount of time to complete before a subsequent input set may be read. While the number of button combinations allows for a large number of actions/movements, systems do not take full advantage of the available analog inputs. As a consequence, an action/movement is either executed in full or not executed at all. Along with controller input, player collisions can induce player movement. Delegating player movement to the animation system takes this responsibility away from the physics engine. Collisions are a large part of the game, and removing this responsibility from the physics engine introduces simulation error with significant ramifications in game play.
In addition to the discrete paradigm, the lack of a dynamic player balance measurement affects game play. Performing a number of actions, such as running around multiple screens, making multiple direction changes, getting bumped off course, or executing repeated crossovers and pivots, does not prevent a player from taking a perfectly stable squared up jump shot at the end of such a wild movement sequence. This aspect results in a bias favoring individual one-on-one play, de-emphasizing the importance of team play.
Finally and most importantly, the inadequate use of artificial intelligence has drastic effects on game play. For example, in real-world basketball a defender is constantly assessing the current threat posed by each offensive player and the ability of his teammates to affect those offensive players. This assessment is used to determine the defender's own optimal position to minimize offensive threats. In the same manner, an offensive player makes the same assessment and attempts to maximize his/her own offensive threat. Using this assessment, players dynamically adjust to the current situation based on their own abilities, the ability of their teammates and opponents, and the relative position of each player on the court. This player behavior is poorly modeled in modern games, resulting in a game flow that does not reflect actual basketball strategies and tactics.
Game play adjustments have been made in recent years in an attempt to address some of these issues. Computer controlled defensive players are allowed to make hyper-speed movements, making it exceedingly difficult for an offensive player to get by the on-ball defender and allowing off-ball defenders to easily recover to proper defensive positions. While this adjustment does indeed counter exploits of the current simulation model, it in no way results in a more realistic game flow. In fact, an adjustment that allows physics to be violated introduces additional simulation error as in-game openings and advantages fail to correlate with those observed in real-world basketball. This problem is observed in many different sports simulation games.